4.2.5 Program Option Modifiers

Some options are “boolean” and control behavior that
can be turned on or off. For example, the mysql
client supports a --column-names
option that determines whether or not to display a row of column
names at the beginning of query results. By default, this option
is enabled. However, you may want to disable it in some instances,
such as when sending the output of mysql into
another program that expects to see only data and not an initial
header line.

To disable column names, you can specify the option using any of
these forms:

--disable-column-names
--skip-column-names
--column-names=0

The --disable and --skip
prefixes and the =0 suffix all have the same
effect: They turn the option off.

The “enabled” form of the option may be specified in
any of these ways:

--column-names
--enable-column-names
--column-names=1

The values ON, TRUE,
OFF, and FALSE are also
recognized for boolean options (not case sensitive).

If an option is prefixed by --loose, a program
does not exit with an error if it does not recognize the option,
but instead issues only a warning:

The --loose prefix can be useful when you run
programs from multiple installations of MySQL on the same machine
and list options in an option file. An option that may not be
recognized by all versions of a program can be given using the
--loose prefix (or loose in an
option file). Versions of the program that recognize the option
process it normally, and versions that do not recognize it issue a
warning and ignore it.

mysqld enables a limit to be placed on how
large client programs can set dynamic system variables. To do
this, use a --maximum prefix with the variable
name. For example, --maximum-query_cache_size=4M
prevents any client from making the query cache size larger than
4MB.